The invention relates to an ignition plug. Such an ignition plug, which is known for example from DE-OS No. 23 63 804, has a capacitor which is built into the ignition plug and arranged so as to be electrically parallel with respect to the spark gap. This capacitor should store enough energy in the vicinity of the spark gap of the ignition plug so that the ionizing initial phase of the spark during the sparking passage at the spark gap of the ignition plug brings about a sure ignition of the fuel vapor/air mixture found in the internal combustion engine. The aforementioned DE-OS No. 23 63 804 also describes such an ignition plug which, in addition, has a preliminary spark gap which is likewise built into the ignition plug and is electrically connected in series with the spark gap. However, the aforementioned DE-OS discloses no indications of an embodiment form of such an ignition plug which can be realized in an economical manner and whose functioning is ensured.
Another ignition plug with a built-in capacitor is known from DE-OS No. 34 04 081; the insulating body of this ignition plug, which comprises a plurality of longitudinal portions, has an average dielectric constant such that this ignition plug has a capacity of 20 to 100 pF, preferably 30 to 80 pF. However, the capacitor of this ignition plug has the object of reducing or suppressing the electromagnetic interference of the internal combustion engine so as to prevent disturbances in radio and television equipment and the like.